JP2017130922A - Reception device, transmission device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission device capable of appropriately transmitting data content or the like of hierarchical modulation in advanced wideband satellite digital broadcasting, a reception device and a program.SOLUTION: The reception device comprises: a receiving unit which receives a broadcast signal; a hierarchy determination unit which determines a hierarchy level; a separation unit which extracts an asset from the broadcast signal; a video processing unit which decodes a video asset separated by the separation unit and outputs a signal of an image; a data processing unit which processes a data asset extracted by the separation unit and outputs a signal of an image; and a presentation unit which overlays the images output by the video processing unit and the data processing unit. The separation unit allocates location information for a data file based on common control information regarding multiple hierarchy levels. If a resolution of the data asset is higher than a resolution of the video asset, the presentation unit reduces the resolution of an image of the data asset in accordance with the resolution of an image of the video asset.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a receiving device, a transmitting device, and a program.

  Hierarchical modulation may be used when distributing video content or the like. Hierarchical modulation is a method in which content of the same content is transmitted in parallel in a plurality of layers, and the amount of information transmitted in each layer is different. For example, in hierarchical modulation in television broadcasting, in addition to transmission using a normal modulation scheme (high hierarchy, high resolution), transmission using a modulation scheme (low hierarchy, low resolution) that is resistant to rainfall or the like is performed in parallel. By using hierarchical modulation, even if the radio wave propagation situation deteriorates due to rainfall or snowfall, the reception device can receive the minimum necessary information, although the amount of information is small, by receiving the lower hierarchy side It becomes possible.

  Non-Patent Document 1, “7.1 Operation of Hierarchical Modulation” (from page 7-34) stipulates the operation of hierarchical modulation in BS digital broadcasting. In BS digital broadcasting, high hierarchy video, high hierarchy audio, data, and SI (service information) are transmitted at a high hierarchy. In addition, low-layer video, low-layer audio, low-layer data, PSI (program specific information), PCR (program clock reference), and ECM (entitlement control message) are transmitted in the low layer. is there. However, the low hierarchy voice may be used as the high hierarchy voice. The lower hierarchy data includes subtitles and character superimpositions.

Hierarchical modulation is also assumed in advanced broadband satellite digital broadcasting (SHV, Super Hi-Vision).
Non-Patent Document 2, “4.8.1 Hierarchical Modulation Reception” (from page 2-20) defines the operation of a receiving apparatus that receives hierarchical modulation. Also, in “7.1.2 Configuration of TLV stream during hierarchical modulation” (from page 7-58) of Non-Patent Document 2, transmission is performed at a high hierarchy and a low hierarchy in the hierarchical modulation of advanced broadband satellite digital broadcasting. Information is defined.

  Note that “5.2 Presentation Function” (from page 3-13) of Non-Patent Document 2 describes restrictions on the combination of screen planes and the resolution of the combined screen plane (particularly “Table 5. 4 Resolution combinations ”).

“BS / Broadband CS Digital Broadcasting Operation Technical Specification ARIB TR-B15 6.9 Edition (Third Volume)”, The Japan Radio Industry Association, December 3, 2015, 2015. "Technical document NEXTVF TR-0004 Advanced Broadband Satellite Digital Broadcasting Operation Version 1.0," Next Generation Broadcasting Promotion Forum, December 25, 2015, 2015

  However, in order to realize hierarchical modulation in advanced broadband satellite digital broadcasting, there are the following problems. One feature of advanced broadband satellite digital broadcasting is that the name space of transmitted content and the space of transmission are separated as separate spaces. Therefore, in order for a receiving apparatus that receives broadcasts to acquire data content in advanced broadband satellite digital broadcasting, it is necessary to follow the information in the following procedure.

That is, first, the receiving apparatus selects a service to be received.
Second, the receiving apparatus acquires MH-AIT (MH-application information table), and the URL (uniform resource locator) of the content (autostart application) described in the MH-AIT. To get.
Third, the receiving apparatus assigns a directory name and a file name to a DDMT (data directory management table), and acquires a node tag (node_tag).
Fourth, the receiving apparatus allocates the acquired node tag to the DAMT (data asset management table). As a result, the receiving apparatus acquires the component tag (component_tag), the MPU sequence number (mpu_sequence_number), and the item ID (item_id). With these three pieces of identification information, the receiving apparatus can allocate an MFU carrying target data.
Fifth, the receiving device acquires a high-level PID (packet ID) from the asset group descriptor.
However, the receiving apparatus does not have means for acquiring a high-level MPU sequence number and item ID. That is, the receiving apparatus can acquire an ES (elementary stream) of high-level data content, but cannot acquire a high-level MPU sequence number and item ID.

  In other words, the conventional technology has a problem that the receiving apparatus cannot appropriately receive the hierarchically modulated data content in the advanced broadband satellite digital broadcasting. This is because, in the prior art, both high-level and low-level PIDs can be obtained, but there is no means for transmitting the MPU sequence numbers and item IDs of both layers to the receiving apparatus. That is, the conventional technique has a problem that there is no means for transmitting the MPU sequence numbers and item IDs of a plurality of layers to the receiving apparatus.

  In addition, for data content, subtitle content, and character super content, it is also an issue to transmit data files of a plurality of layers to a receiving device by an efficient transmission method.

  The present invention has been made on the basis of the above-mentioned problem recognition, and is intended to provide a transmission device, a reception device, and a program capable of appropriately transmitting hierarchical modulation data content in advanced broadband satellite digital broadcasting. It is what.

  [1] In order to solve the above-described problem, a receiving device according to an aspect of the present invention includes a receiving unit that receives a broadcast signal, and any of a plurality of hierarchies when the broadcast signal is hierarchically modulated. A hierarchy determining unit that determines whether or not to receive a video asset and a data asset of the hierarchy determined by the hierarchy determining unit from the broadcast signal; A video processing unit that outputs an image signal by decoding the video asset extracted by the separation unit; and a data processing that outputs an image signal by processing the data asset extracted by the separation unit. And a presentation unit that overlays and presents images output from the video processing unit and the data processing unit on a screen. The receiving unit receives a broadcast signal including a single data file entity shared between the plurality of hierarchies with respect to the data asset, and the separating unit receives the data asset with respect to the data asset. The data file is extracted based on location information common to a plurality of hierarchies, and the presentation unit has a higher resolution of the image resolution of the data asset than the resolution of the image of the video asset. In some cases, the image is processed so as to reduce the resolution of the image by the data asset in accordance with the resolution of the image by the video asset.

  In the reference aspect, in the receiving device, the separation unit obtains the location information common to the plurality of layers by referring to a common application information table regarding the plurality of layers with respect to the data asset. It is characterized by.

Further, in the above-described receiving device, the separation unit extracts the subtitle asset and the character super asset of the hierarchy determined by the hierarchy determination unit from the broadcast signal, A caption processing unit that outputs an image signal by processing the caption asset extracted by the separation unit, and a character super process that outputs an image signal by processing the character super asset extracted by the separation unit And the reception unit receives a broadcast signal including an entity of a single data file shared between the plurality of hierarchies with respect to the caption asset and the character super asset. The separation unit includes the plurality of hierarchies for each of the caption asset and the character super asset. The location information of the data file is allocated based on the control information of each, and the data file is extracted based on the location information, and the presentation unit includes the subtitle asset rather than the image resolution of the video asset. If the resolution of the image according to is higher resolution, the image is processed so as to reduce the resolution of the image according to the subtitle asset in accordance with the resolution of the image according to the video asset, and then based on the video asset. When the image based on the subtitle asset is overlaid on the image, and the resolution of the image based on the character super asset is higher than the resolution of the image based on the video asset, the resolution of the image based on the video asset is set. At the same time, the resolution of the image by the character super asset is lowered. After processing the image, overlaying the image based on the subtitle assets into the image based on the video asset, characterized in that.
In other words, the receiving unit receives a broadcast signal including the same data file entity among the plurality of layers with respect to the caption asset and the character super asset.

  The transmitting apparatus according to the reference aspect includes a video supply unit that supplies a video asset including a plurality of layers for hierarchical modulation, and a data supply unit that supplies a data asset including a plurality of layers for hierarchical modulation. A control information setting unit for setting control information for transmission, a multiplexing unit for generating a broadcast signal including at least the video asset, the data asset, and the control information, and the multiplexing unit. A transmission unit that transmits a broadcast signal, and the control information setting unit represents the location of the data file common to the plurality of layers in the application information table common to the plurality of layers with respect to the data asset. The location information is stored.

Further, in the reference aspect, in the transmission device described above, a subtitle supply unit that supplies a common subtitle asset to a plurality of hierarchies for hierarchical modulation, and a common character super asset to a plurality of hierarchies for hierarchical modulation A character super supply unit, wherein the multiplexing unit further generates the broadcast signal including the caption asset and the character super asset, and the control information setting unit relates to the caption asset. A caption location information representing the location of a single data file shared between layers is set, and a character super location representing the location of a single data file shared between the plurality of layers is set for the character super asset. It is characterized by setting information.
In other words, the control information setting unit sets subtitle location information representing the location of a data file common to the plurality of hierarchies for the subtitle asset, and is common to the plurality of hierarchies for the character super asset. Set the character super location information indicating the location of the data file.

  [2] One embodiment of the present invention is a program for causing a computer including a receiving unit that receives a broadcast signal to function as the receiving device according to [1] above.

  According to the present invention, it becomes possible to appropriately transmit hierarchical modulation data contents in advanced broadband satellite digital broadcasting. Further, when data files of a plurality of layers are shared, the transmission band can be efficiently used.

It is a schematic block diagram which shows the structure of the broadcast system by 1st Embodiment of this invention. It is a block diagram which shows schematic function structure of the receiver by the same embodiment. It is the schematic which classified and showed the structure of the broadcast signal by the hierarchical modulation by the embodiment as a table | surface. It is the schematic which shows the structure of a part of control information contained in the broadcast signal which the receiver by the same embodiment receives. It is the schematic which shows the structure of the packet of MMTP (MMT protocol) used in the embodiment. It is the schematic showing the relationship of the control information from the file name in AIT by the same embodiment to the entity of the said file. It is the schematic which shows the method of the screen presentation of a video asset and another asset at the time of high hierarchy reception and low hierarchy reception by the same embodiment. It is the schematic which shows the pattern of the combination of the resolution of a video content and the resolution as other content by the embodiment. It is a block diagram which shows the schematic function structure of the transmitter by the embodiment. It is a schematic block diagram which shows the structure of the broadcast system by 2nd Embodiment. It is a block diagram which shows schematic function structure of the receiver by the same embodiment. It is the schematic which shows the example of the value of the protocol identification in the MH-transmission protocol descriptor by the same embodiment, and the definition of the meaning. It is a block diagram which shows the schematic function structure of the transmitter by the embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]
FIG. 1 is a schematic configuration diagram showing a configuration of a broadcasting system according to the present embodiment. In the figure, reference numeral 1 denotes a broadcasting system. The broadcast system 1 includes a transmission device 3, a broadcast satellite 5, and a reception device 7.

The transmission device 3 outputs a broadcast signal including video, audio, subtitles, text super, and data content. This broadcast signal is transmitted toward the broadcast satellite 5.
The broadcast satellite 5 is an artificial satellite that transmits and receives broadcast signals using radio waves. A signal output from the transmission device 3 and transmitted (uplink) from the earth station is received, and the signal is transmitted (downlink) to the reception device 7 on the earth.
The receiving device 7 receives a broadcast signal transmitted from the broadcast satellite 5, demodulates the content (video, audio, subtitles, text super, and data) included in the received broadcast signal and presents it to the user.

  In the present embodiment, the broadcast signal is a signal of advanced broadband satellite digital broadcasting. The broadcast signal is transmitted by the MMT (MPEG Media Transport) method. In other words, the payload of assets (video, audio, data, subtitles, etc.) constituting the broadcast service is transmitted in the MPU / MFU configuration by the MMT method. Here, MPU is an abbreviation for “Media Processing Unit”. MFU is an abbreviation for “Media Fragment Unit”.

In FIG. 1, one transmitting device, one broadcasting satellite, and one receiving device are shown, but there may be a plurality of receiving devices that receive broadcast signals. For example, tens of millions or more of receiving apparatuses may exist.
Further, FIG. 1 shows a case where the receiving device receives a broadcast signal transmitted via a broadcast satellite, but the broadcast signal may be transmitted by terrestrial (wireless) or a cable.

  FIG. 2 is a block diagram showing a schematic functional configuration of the receiving apparatus according to this embodiment. As shown in the figure, the receiving device 7 includes a receiving unit 21, a hierarchy determining unit 23, a separating unit 25, a video processing unit 27, an audio processing unit 29, a data processing unit 31, and a caption processing unit 33. And a character super processing unit 35 and a presentation unit 37.

The receiving unit 21 receives a broadcast signal and demodulates it. The receiving unit 21 determines whether or not the service being received is hierarchically modulated by referring to the control information. In the case of hierarchical modulation, the received broadcast signal is passed to the hierarchy determination unit 23 in order to determine the hierarchy to be received (extracted). In addition, the receiving unit 21 acquires the determination result (whether it is a high layer or a low layer) of the layer determination unit 23, and subsequently receives any layer according to the determination result.
In addition, you may make it perform a hierarchy determination for every predetermined time interval. Thereby, it is possible to switch from the higher hierarchy to the lower hierarchy, or conversely, from the lower hierarchy to the higher hierarchy, depending on the reception status of the broadcast signal.
Note that the receiving unit 21 according to the present embodiment receives a broadcast signal including the same data file entity among a plurality of hierarchies, at least with respect to data assets. Similarly, for subtitle assets and text super assets, a broadcast signal including the same data file entity may be received between a plurality of layers. Here, the “same data file” refers to exactly the same data as a file, and does not refer to a plurality of files in which only a part of the data is common.

  The hierarchy determination unit 23 determines, based on the broadcast signal received by the reception unit 21, whether a higher hierarchy or a lower hierarchy should be received when the service being received is hierarchically modulated. Specifically, the hierarchy determination unit 23 monitors the error rate of the higher hierarchy signal and determines whether or not the error rate is equal to or higher than a predetermined threshold. When the error rate is equal to or higher than the threshold, the hierarchy determination unit 23 determines to receive the lower hierarchy. Conversely, when the error rate is less than the threshold value, the hierarchy determination unit 23 determines to receive a higher hierarchy. The hierarchy determination unit 23 notifies the reception unit 21 of the determination result (whether a higher hierarchy or a lower hierarchy should be received).

  The separation unit 25 extracts video assets, audio assets, data assets, subtitle assets, and character super assets, respectively. When the received broadcast signal is hierarchically modulated, the separation unit 25 extracts data of each asset in the hierarchy determined by the hierarchy determination unit 24. In addition, regarding the data asset, the separation unit 25 allocates the location information of the data file based on common control information regarding a plurality of hierarchies. Specifically, for the data asset, the separation unit 25 stores a path stored as information common to both hierarchies in the same application information table when receiving either a high hierarchy or a low hierarchy. Get name information. Then, the separation unit 25 allocates the location of the data file based on the acquired path name. The control information related to the data asset will be described later.

The video processing unit 27 processes (decodes) the video asset extracted by the separation unit 25, and outputs the video (image) obtained as a result to the presentation unit 37.
The audio processing unit 29 processes (decodes) the audio asset extracted by the separation unit 25 and outputs the resulting audio to the presentation unit 37.
The data processing unit 31 processes the data asset extracted by the separation unit 25 and outputs an image or the like obtained as a result to the presentation unit 37.
The caption processing unit 33 processes the caption asset extracted by the separation unit 25, and outputs the video (image) obtained as a result to the presentation unit 37.
The character super processing unit 35 processes the character super asset extracted by the separation unit 25, and outputs a video (image) obtained as a result to the presentation unit 37.

  The presentation unit 37 synthesizes the video processing unit 27, the audio processing unit 29, the data processing unit 31, the caption processing unit 33, and the character super processing unit 35, and outputs them as video and audio. At this time, the presentation unit 37 overlays the video (or image) supplied from each unit and outputs it as a single screen.

  When the resolution of the image based on the data asset is higher than the resolution of the image based on the video asset, the presentation unit 37 reduces the resolution of the image based on the data asset in accordance with the resolution of the image based on the video asset. After the image is processed as described above, the image based on the video asset and the image based on the data asset are overlaid. In addition, when the resolution of the image based on the caption asset is higher than the resolution of the image based on the video asset, the presentation unit 37 reduces the resolution of the image based on the caption asset in accordance with the resolution of the image based on the video asset. After the image is processed as described above, the image based on the caption asset is overlaid on the image based on the video asset. In addition, when the resolution of the image based on the text super asset is higher than the resolution of the image based on the video asset, the presentation unit 37 matches the resolution of the image based on the video asset with the resolution of the image based on the text super asset. Then, the image is processed so as to lower the image, and then the image based on the video asset is overlaid on the image based on the video asset. Note that the process of changing the resolution of the image (enlargement or reduction of the image) by the presentation unit 37 will be described in detail later.

  FIG. 3 is a schematic diagram showing the configuration of broadcast signals by hierarchical modulation received by the receiving device 7 as a table. In the figure, control information (A) across services transmitted at high and low layers is divided into assets transmitted at high / low layers and examples of control information (B) of services that perform hierarchical modulation. Various information is shown.

In FIG. 5A, information transmitted at a lower layer includes information such as TLV-NIT, AMT, PA message (PLT), CA message (when CAS exists), and NTP. TLV is an abbreviation for “Type Length Value”. NIT is an abbreviation for “Network Information Table”. AMT is an abbreviation for “Address Map Table”. PA is an abbreviation for “Package Access”. PLT is an abbreviation for “Package List Table”. CA is an abbreviation for “Conditional Access”. CAS is an abbreviation for “Conditional Access System”. NTP is an abbreviation for “Network Time Protocol”.
TLV-NIT and AMT are a kind of table defined as TLV-SI. TLV-NIT and AMT include information indicating the configuration and characteristics of the broadcast network. The PA message is one of messages defined as MMT-SI and can include all tables. That is, the PA message serves as an entry point for the MMT control message. The CA message is a message that transmits information related to the conditional access method. NTP is a protocol for transmitting time information (current time).
SI is an abbreviation for “Signaling Information”.

In FIG. 6A, what is transmitted in the higher hierarchy is MMT-SI (except those listed as information in the lower hierarchy) and EMM (provided there is CAS).
MMT-SI is a transmission control signal indicating the configuration of the MMT package. EMM is an abbreviation for “Entitlement Management Message”. The EMM transmits contract information and the like in CAS.

In FIG. 5B, the ones transmitted in the lower hierarchy are low hierarchy video, low hierarchy audio, low hierarchy data content, low hierarchy subtitles, PA message (MPT), ECM (if CAS exists), data Transmission message, MH-AIT, EMT. MPT is an abbreviation for “MMT Package Table”. ECM is an abbreviation for “Entitlement Control Message”. AIT is an abbreviation for “Application Information Table”.
In FIG. 5B, what can be transmitted at a higher hierarchy is a higher hierarchy video, higher hierarchy audio, data content, and subtitles. Each of these may be transmitted in a higher hierarchy.
In addition, regarding data content and subtitles, a specific configuration method of low-level content and high-level content in the present embodiment will be described in detail later.

  In the present embodiment, a high hierarchy file and a low hierarchy file are common for data assets. Therefore, the receiving device 7 can acquire the data file based on the control information described below regardless of whether the reception is in the higher hierarchy or the lower hierarchy.

  FIG. 4 is a schematic diagram showing a configuration of part of control information included in a broadcast signal received by the receiving device 7. The relationship of the control information until the receiving device 7 reaches the file entity of the data asset will be described with reference to FIG. The receiving unit 21 in the receiving device 7 selects a specific service by the viewer's operation or the like. And the receiving part 21 acquires MPT of the service. Information indicating whether or not the service is hierarchically modulated is included in the asset group descriptor of the MPT. Further, in the transmission identification information in the MPT, an asset ID (asset_id), a component tag (component_tag), and a packet ID (packet_id) are stored in association with each other. That is, the relationship between asset ID, component tag, and packet ID is defined in MPT.

The MPT application service descriptor includes AIT transmission information and data transmission message transmission information. An AIT can be allocated based on the AIT transmission information. A data transmission message can be allocated based on the data transmission message transmission information.
The AIT includes URL (Uniform Resource Locator) information indicating the location of an application (HTML file) written in HMTL (Hypertext Markup Language). The URL includes directory name and file name information of the application file.

DDMT, DCCT, and DAMT are included in the data transmission message.
The DDMT (data directory management table) holds tree-structured directories and files and node tags (node_tag) corresponding to them as node tag information. The node tag is a unique value for each directory (however, a directory having a file immediately below) and each file.
The DCCT includes PU information. The PU information is information on the MPU included in the PU. In the PU information, one or more MPUIDs (mpu_id) are stored in association with the PU tag (PU_tag). The MPUID is information of upper 16 bits of the MPU sequence number (mpu_sequence_number).
DAMT (data asset management table) includes item (file) transmission information. The item transmission information holds the correspondence between the MPU sequence number, the file-unit node tag, the item ID, and the item version in association with the combination of the component tag (component_tag) and the download ID (download_id). If the MPU is a directory unit, the node tag of the corresponding directory is described.

  By configuring the control information in this way, it is possible to acquire a node tag that can uniquely identify these directories and files by referring to the DDMT from the directory names and file names included in the AIT. Furthermore, a component tag (component_tag), an MPU sequence number (mpu_sequence_number), and an item ID (item_id) can be acquired by referring to DAMT from the acquired node tag. This makes it possible to allocate an MFU that stores an object such as a target file.

  As described above, the high-level data content and the low-level data content are shared. Therefore, the transmission band can be efficiently used for the data content.

FIG. 5 is a schematic diagram showing the configuration of an MMTP (MMT protocol) packet. As shown in the figure, a packet is composed of a header and a payload.
Part of the header is an extension header. A packet ID (packet_id) is included in an area in the header that is not an extension header. In addition, a download ID is included in the extension header.
The payload is composed of a header and a body. This header includes an MPU sequence number (mpu_sequence_number). Further, this body includes an item ID (item_id) and the actual file.

  FIG. 6 is a schematic diagram showing the relationship of control information from the file name in the AIT until reaching the entity of the file. Based on the file name in AIT (fileName in the figure), the node tag of the file can be assigned by referring to DDMT. Also, by referring to DAMT based on the node tag, the component tag, download ID, and item ID of the file can be assigned. Further, by referring to the transmission identification information in the MPT based on the acquired component tag, a packet ID corresponding to the component tag can be assigned. As a result, three types of identification information corresponding to the original file name, that is, a packet ID, a download ID, and an item ID are obtained. With these three types of identification information, the reception device 7 can acquire the file entity of the asset as shown in FIG.

The transmission method of the data asset file entity and the control information related thereto have been described above with reference to FIGS. 4, 5, and 6.
Note that the subtitle asset and the character super asset may be transmitted in the same manner as the data file entity between the hierarchies. In that case, for each of the caption asset and the character super asset, the substance of the data file constituting the asset is shared between the high hierarchy and the low hierarchy. Further, common information is stored for each of the high hierarchy and the low hierarchy as control information for assigning these data files on the receiving device 7 side.
Thereby, similarly to the data asset, the transmission amount of the substance of the data file to be transmitted can be reduced for the caption asset and the character super asset. As for subtitle assets and character super assets, text data occupies a large portion of the actual data file. Therefore, by making the data file common between the hierarchies, it is possible to improve the transmission efficiency without greatly affecting the quality of presentation on the receiving device side. In other words, even if there is a slight influence on the quality of presentation, it is possible to perform a reduction operation in which the minimum necessary information is transmitted.

As for the data asset, the substance of a single data file is transmitted, and the data file is shared among a plurality of hierarchies. At this time, each of the plurality of hierarchies may be described using an asset group descriptor as the definition of the data asset in the MPT. At this time, the plurality of hierarchies are associated with one asset (data asset). Conversely, the asset group descriptor may not be used as the definition of the data asset in the MPT.
In addition, regarding the subtitle asset, the substance of the data file may be transmitted, and the data file may be shared among a plurality of layers. When such sharing is performed, each of the plurality of hierarchies may be described using an asset group descriptor as a definition of a caption asset in MPT. At this time, the above-described plurality of hierarchies are associated with one asset (caption asset). Conversely, the asset group descriptor may not be used as the definition of the caption asset in the MPT.
In addition, regarding the character super asset, the substance of the data file may be transmitted, and the data file may be shared among a plurality of layers. When such sharing is performed, each of the plurality of hierarchies may be described using an asset group descriptor as the definition of the character super asset in the MPT. At this time, the above-described plurality of hierarchies are associated with one asset (character super asset). Conversely, the asset group descriptor may not be used as the definition of the character super asset in the MPT.

  FIG. 7 is a schematic diagram showing how to present video assets and other assets on the screen when receiving a high hierarchy and a low hierarchy. FIG. 4A shows a case where data content and video are overlaid and presented. FIG. 5B shows a case where subtitle content and video are overlaid and presented.

In the example shown in FIG. 5A, the video asset is transmitted at a resolution of 8K (horizontal 7680 pixels × vertical 4320 pixels) in the high hierarchy, and a resolution of 2K (horizontal 1920 pixels × vertical 1080 pixels) in the low hierarchy. It is transmitted with. On the other hand, the data asset (data content) is transmitted as data for presentation at a resolution of 8K (horizontal 7680 pixels × vertical 4320 pixels) in both the high hierarchy and the low hierarchy. As described above, the data content in the higher hierarchy and the data content in the lower hierarchy are transmitted as the same file. In this case, the presentation unit 37 of the receiving device 7 appropriately adjusts the presentation size of the video and data based on the resolution information output from the video processing unit 27 and the resolution information output from the data processing unit 31. To do.
Specifically, it is as follows. When the receiving device 7 receives the high hierarchy, the presentation unit 37 simply overlays the high hierarchy video (resolution is 8K) and the data content (resolution 8K). In other words, since the resolution of the video and the resolution of the data content both match at 8K, the presentation unit 37 does not need to enlarge or reduce either the video or the data.
When the receiving device 7 receives the lower hierarchy, the presentation unit 37 reduces the data content (resolution 8K) to 2K resolution and then overlays the lower hierarchy video (resolution 2K). That is, in order to match 2K which is the resolution of the video, the presentation unit 37 reduces the data content originally produced to be displayed at the 8K resolution to the 2K resolution.

In the example shown in FIG. 5B, the video asset is transmitted at a resolution of 8K (horizontal 7680 pixels × vertical 4320 pixels) in the high hierarchy, and a resolution of 2K (horizontal 1920 pixels × vertical 1080 pixels) in the low hierarchy. It is transmitted with. On the other hand, subtitle assets (subtitle content) are transmitted as subtitles for presentation at a resolution of 4K (horizontal 3840 pixels × vertical 2160 pixels) in both high and low layers. As described above, the subtitle content in the higher hierarchy and the subtitle content in the lower hierarchy are transmitted as the same file, that is, as a single file entity. In this case, the presentation unit 37 of the reception device 7 appropriately adjusts the presentation size of the video and the caption based on the resolution information output from the video processing unit 27 and the resolution information output from the caption processing unit 33. To do.
Specifically, it is as follows. When the receiving device 7 receives the high hierarchy, the presentation unit 37 expands the subtitle content (resolution 4K) to the resolution of 8K, and then overlays it with the high hierarchy video (resolution is 8K). That is, in order to match the video resolution of 8K, the presentation unit 37 enlarges the caption content originally produced to be displayed at the 4K resolution to the 8K resolution.
When the receiving device 7 receives the lower hierarchy, the presentation unit 37 reduces the subtitle content (resolution 4K) to 2K resolution, and then overlays it with the lower hierarchy video (resolution 2K). That is, in order to match 2K that is the resolution of the video, the presentation unit 37 reduces the subtitle content that was originally produced to be displayed at the 4K resolution to the 2K resolution.

That is, the presentation unit 37 performs enlargement or reduction processing as necessary so that the resolution of the data content, the caption content, and the text super content matches the resolution of the video.
Processing of resolution enlargement and reduction itself can be performed by existing technology.

FIG. 8 is a schematic diagram showing a combination pattern of the resolution of video content (main line video) and the resolution of other content (content displayed on the screen as an image or the like) in the present embodiment. In the matrix shown in the figure, the vertical direction (row direction) represents a variation in the resolution of the video content. The horizontal direction (column direction) represents the type of content other than video and the variation of the resolution of each content. In the matrix, a circle indicates that a combination of resolutions (rows and columns) is allowed. In the matrix, no mark indicates that a combination of the resolutions (rows and columns) is not allowed (contents in such a combination are not transmitted from the transmission device 3 side). Regarding the resolution of the video content, the first row is 8K (horizontal 7680 pixels × vertical 4320 pixels), the second row is 4K (horizontal 3840 pixels × vertical 2160 pixels), and the third row is 2K (horizontal 1920 pixels × vertical). 1080 pixels). In the column direction, the first column to the third column correspond to the resolution of the data content (HTML document). The first column corresponds to 8K (horizontal 7680 pixels × vertical 4320 pixels), the second column corresponds to 4K (horizontal 3840 pixels × vertical 2160 pixels), and the third column corresponds to 2K (horizontal 1920 pixels × vertical 1080 pixels). .
The fourth column and the fifth column correspond to the resolutions of the caption content and the character super content. The fourth column corresponds to 4K (horizontal 3840 pixels × vertical 2160 pixels), and the fifth column corresponds to 2K (horizontal 1920 pixels × vertical 1080 pixels).

As shown in the figure, the following seven combinations are allowed as the resolution of the video content and the resolution of the data content.
(1) The resolution of video content is 8K and the resolution of data content is 8K
(2) The video content resolution is 8K and the data content resolution is 4K.
(3) The video content resolution is 4K and the data content resolution is 4K.
(4) The video content resolution is 4K and the data content resolution is 2K.
(5) The video content resolution is 2K and the data content resolution is 8K.
(6) The video content resolution is 2K and the data content resolution is 4K.
(7) The video content resolution is 2K and the data content resolution is 2K.
It should be noted that other than the above seven combinations are not allowed.

Further, as shown in the figure, there are the following five combinations that are allowed as the resolution of the video content and the resolution of the caption content or the text super content.
(8) The resolution of video content is 8K, and the resolution of subtitles or text super is 4K.
(9) The resolution of video content is 4K, and the resolution of subtitles or text super is 4K.
(10) The resolution of the video content is 4K, and the resolution of subtitles or text super is 2K.
(11) The resolution of the video content is 2K, and the resolution of subtitles or text super is 4K.
(12) The resolution of video content is 2K, and the resolution of subtitles or text super is 2K.
Other than the above five combinations are not allowed.

  The transmission device 3 transmits a broadcast signal based on the combination of resolutions described above. The receiving device 7 receives and processes the broadcast signal.

  Also in the prior art, it is allowed to overlay the resolution of data content, subtitle content, character super content, etc. in accordance with the resolution of video content. However, even in the prior art, in order to match the resolution of the video content, it is not allowed to change the resolution of the data content, the caption content, the character super content, or the like in a decreasing direction.

  Document “Technical document NEXTVF TR-0004, Advanced Broadband Satellite Digital Broadcasting Operation Manual Version 1.0”, General-purpose Next Generation Broadcasting Promotion Forum, December 25, 2015, Non-Patent Document 2 “Table 5.4 Resolution Combinations” on page 16 describes restrictions on the resolutions of the screen planes to be combined. Also in this table, when the resolution of the main line video is 2K (1920 × 1080), the combination that the resolution of the data content (HTML document) is 4K (3840 × 2160) or 8K (7680 × 4320) is not allowed. . Further, in the table, when the resolution of the main line video is 2K (1920 × 1080), it is not permitted to set the resolution of the caption or the character superimpose to 4K (3840 × 2160).

  The reason is that changing the resolution of the presentation of data content, subtitles, and character supermarkets to be smaller than the resolution originally intended by the creator is not preferable because it causes loss of information as an image. For example, a horizontal or vertical straight line having a width of one pixel may disappear when the resolution is reduced to half or quarter. Alternatively, it is conceivable that whether or not the straight line disappears depends on the mounting of the receiving device when the resolution is changed in the direction of decreasing the resolution.

  In the present embodiment, it is allowed to change the resolution of data content, subtitle content, and character super content in a direction of decreasing on the receiving device side. Specifically, the transmission device 3 transmits signals of data content, subtitle content, and character super content having a resolution higher than that of video content, particularly in a lower hierarchy. When the receiving device 7 receives the broadcast signal and presents content in a lower hierarchy, the receiving device 7 reduces the data content, subtitle content, and character super content (that is, changes the resolution to be smaller).

  Note that the resolution values shown in FIG. 8 are merely examples, and resolutions different from those illustrated may be used. One point of the present embodiment is to share the substance of the data file to be transmitted among a plurality of hierarchies in data content, subtitle content, and character super content. Another point is to allow data content, subtitle content, and text super content having a resolution higher than that of the video, and appropriately enlarge / reduce the video content to overlay the video content.

  FIG. 9 is a block diagram illustrating a schematic functional configuration of the transmission apparatus according to the present embodiment. As shown in the figure, the transmission device 3 includes a video supply unit 51, an audio supply unit 53, a data supply unit 55, a subtitle supply unit 57, a character super supply unit 59, a multiplexing unit 61, and a transmission. A unit 63 and a control information setting unit 65 are included.

The video supply unit 51 supplies video assets including a plurality of layers for hierarchical modulation.
The audio supply unit 53 supplies an audio asset including a plurality of layers for hierarchical modulation.
The data supply unit 55 supplies a data asset including a plurality of layers for hierarchical modulation.
The subtitle supply unit 57 supplies subtitle assets including a plurality of layers for hierarchical modulation.
The character super supply unit 59 supplies a character super asset including a plurality of layers for hierarchical modulation.

  The multiplexing unit 61 generates a broadcast signal including at least a video asset, a data asset, and control information. The multiplexing unit 61 further generates a broadcast signal including audio assets, subtitle assets, and character super assets.

  The transmission unit 63 transmits the broadcast signal generated by the multiplexing unit 61. The transmitter 63 transmits a broadcast signal of the advanced broadband satellite digital broadcast by the MMT method.

The control information setting unit 65 sets control information for transmission. The control information setting unit 65 stores location information indicating the location of a data file common to a plurality of hierarchies in an application information table common to a plurality of hierarchies regarding the data asset.
Further, when the same data file is shared between a plurality of hierarchies regarding the subtitle asset, the control information setting unit 65 sets the subtitle location information indicating the location of the common data file in each of the plurality of hierarchies. .
Further, when the same data file is shared between a plurality of hierarchies regarding the character super asset, the control information setting unit 65 sets character super location information indicating the location of the data file common to each of the plurality of hierarchies. Set.

As described above, how to transmit each asset in the present embodiment is as follows.
For data assets, a single data file entity is transmitted. And for a data asset, multiple tiers share that single data file.
As for caption assets, the same data file entity may be shared among a plurality of layers, or the data file entity of each layer may be transmitted without such sharing.
Regarding character super assets, the same data file entity may be shared among a plurality of hierarchies, or the data file entity of each hierarchy may be transmitted without such sharing. .
Note that whether or not the same data file entity is shared among a plurality of hierarchies for a caption asset and whether or not the same data file entity is shared between a plurality of hierarchies for a character super asset are mutually independent. . Each subtitle asset and character super asset can be determined and shared.

[Second Embodiment]
Next, a second embodiment will be described. Note that description of matters common to the previous embodiment may be omitted. In the following, description will be made centering on matters specific to the present embodiment.
FIG. 10 is a schematic configuration diagram showing the configuration of the broadcast system according to the present embodiment. In the figure, reference numeral 2 denotes a broadcasting system. The broadcast system 2 includes a transmission device 4, a broadcast satellite 6, and a reception device 8. The broadcast system 2 has a configuration similar to the broadcast system 1 in the previous embodiment. However, in the broadcast system 2, the hierarchical modulation scheme for data content, subtitle content, text super content, and the like is different from that of the broadcast system 1. With this difference, some of the functions of the transmission device 4 are different from those of the transmission device 3, and some of the functions of the reception device 8 are different from those of the reception device 7.

Similar to the transmission device 3 in the previous embodiment, the transmission device 4 outputs a broadcast signal including video, audio, subtitles, text super, and data content.
The broadcast satellite 6 transmits and receives broadcast signals using radio waves, similar to the broadcast satellite 5 in the previous embodiment.
The reception device 8 receives a broadcast signal transmitted from the broadcast satellite 5 as with the reception device 7 in the previous embodiment.
Also in the present embodiment, only one receiving device 8 is shown in FIG. 10, but there are actually a plurality of receiving devices 8.
FIG. 10 shows a case where the receiving device receives a broadcast signal transmitted via a broadcast satellite, but the broadcast signal may be transmitted by terrestrial (wireless) or a cable.

  In the present embodiment, the transmission device 4 transmits data content for a low hierarchy and data content for a high hierarchy. Further, for each layer, a URL unique to the data content of that layer is defined. The receiving device 8 determines a layer to be received, and allocates the substance of the data content of the layer based on the URL corresponding to the determined layer. Details of how to allocate data contents for each layer will be described later.

  FIG. 11 is a block diagram illustrating a schematic functional configuration of the receiving apparatus according to the present embodiment. As shown in the figure, the receiving device 8 includes a receiving unit 22, a hierarchy determining unit 24, a separating unit 26, a video processing unit 28, an audio processing unit 30, a data processing unit 32, and a caption processing unit 34. And a character super processing unit 36 and a presentation unit 38.

The receiving unit 22 receives a broadcast signal.
The hierarchy determination unit 24 determines, based on the received broadcast signal, which of the plurality of hierarchies is received when the received broadcast signal is hierarchically modulated.

The separation unit 26 extracts at least a video asset and a data asset in the hierarchy determined by the hierarchy determination unit 24 from the received broadcast signal. Further, the separation unit 26 further extracts audio assets, subtitle assets, and character super assets in the hierarchy determined by the hierarchy determination unit 24 from the broadcast signal.
Also, the separation unit 26 uses the hierarchy determination unit 24 to determine the location information (for example, base directory name) of each of a plurality of levels stored in a predetermined table (for example, application information table) for the data asset. The data file is extracted based on the determined location information of the hierarchy. The location where the location information (for example, base directory name) of each layer is stored is, for example, in the MH-transmission protocol descriptor in the application information table.
Similarly, for the subtitle asset and the character super asset, the separation unit 26 also determines the hierarchy among the location information (for example, the base directory name) of each of the plurality of hierarchies stored in the predetermined table for each asset. The data file may be extracted based on the location information of the hierarchy determined by the determination unit 24.

The video processing unit 28 outputs an image (video) signal by decoding the video asset extracted by the separation unit 26.
The audio processing unit 30 outputs an audio signal by decoding the audio asset extracted by the separation unit 26.
The data processing unit 32 processes the data asset extracted by the separation unit 26 and outputs an image signal.
The caption processing unit 34 outputs an image signal by processing the caption asset extracted by the separation unit 26.
The character super processing unit 36 processes the character super asset extracted by the separation unit 26 to output an image signal.

  The presentation unit 38 overlays and presents at least the images output from the video processing unit 28 and the data processing unit 32 on the screen. The presentation unit 38 also overlays and displays the image output from the caption processing unit 34 and the image output from the character super processing unit 36 on the screen. The presentation unit 38 presents the sound output from the sound processing unit 30.

Here, control information in this embodiment, particularly control information indicating the location of the data file will be described.
The MH-application information table (AIT) itself is transmitted in a low hierarchy.
Then, an application for autostart (automatic activation) is defined in the MH-application information table. In addition, a plurality of URLs for each hierarchy can be described in association with the application. Specifically, an MH-transmission protocol descriptor is described for each of the high and low layers as an application loop descriptor in the MH-application information table. Thereby, it is possible to define a base directory corresponding to each hierarchy. As an example, the base directory for the high hierarchy is “/ shv”, and the base directory for the low hierarchy is “/ shv-L”. The base directory name is not limited to these. It is sufficient if the base directory names for the high hierarchy and the low hierarchy can be distinguished.

  On the other hand, the MH-simple application location descriptor is shared by each layer. The MH-simple application location descriptor defines the name of a file (path) placed under the base directory. As an example, it is assumed that the path name of the high-level file and the path name of the low-level file are “/menu/top.html”. That is, the file name described in the MH-simple application location descriptor shared by the high hierarchy and the low hierarchy is “/menu/top.html”. The path name defined here is also arbitrary.

  According to the above example, “/shv/menu/top.html” is defined as the URL for the higher hierarchy. Also, “/shv-L/menu/top.html” is defined as the URL for the lower hierarchy. In addition, different contents (that is, for the high hierarchy and for the low hierarchy) are produced and transmitted in correspondence with each URL. The base directory name and the path name below the base directory name may be appropriately determined by the operation of the broadcaster.

  In the prior art, it was not possible to describe definitions for a plurality of layers in the MH-transmission protocol descriptor. However, in this embodiment, as described above, the MH-transmission protocol descriptor is described for each of the higher and lower layers. For this reason, as a protocol identification (protocol_id, protocol ID) in the MH-transmission protocol descriptor, a value for a high layer and a value for a low layer are used properly.

  FIG. 12 is a schematic diagram illustrating an example of a definition of a protocol identification value and its meaning in the MH-transmission protocol descriptor. As shown in the figure, when the value of the protocol identification is 0x0005 (hexadecimal notation), it represents data content (non-timed, content not associated with the presentation time) transmitted by the MMT by the MMT. . In addition, when the value of the protocol identification is 0x0006 (hexadecimal representation), it represents data content (non-timed) by a lower hierarchy transmitted by MMT. In addition, when the protocol identification is 0x0003 (hexadecimal representation), the transmission is based on HTTP or HTTP5. In addition, when the protocol identification is 0x0004 (hexadecimal expression), transmission is performed by a data carousel. Also, reserved values 0x0001 to 0x0003 and 0x0007 to 0xffff are reserved as protocol identification values.

  Thus, by separating the values of the protocol identification for the high hierarchy and the protocol identification for the low hierarchy, the MH-transmission protocol identifier for the high hierarchy and the MH-transmission protocol identifier for the low hierarchy are included in the AIT. Can be stored. Then, it is possible to define unique base directory names in the MH-transmission protocol identifiers for the high hierarchy and the low hierarchy. Then, the receiving device 8 obtains the location of the data file of the hierarchy to be received based on the URLs of the high hierarchy and the low hierarchy, and acquires the data files.

  The transmission device 4 transmits a broadcast signal including the control information described above. Further, the receiving device 8 receives the broadcast signal, determines the hierarchy based on the received broadcast signal, acquires and presents the content of the hierarchy determined as the determination result.

  FIG. 13 is a block diagram illustrating a schematic functional configuration of the transmission apparatus according to the present embodiment. As shown in the figure, the transmission device 4 includes a video supply unit 52, an audio supply unit 54, a data supply unit 56, a subtitle supply unit 58, a character super supply unit 60, a multiplexing unit 62, and a transmission. Unit 64 and a control information setting unit 66.

The video supply unit 52 supplies video assets including a plurality of layers for hierarchical modulation.
The audio supply unit 54 supplies an audio asset including a plurality of layers for hierarchical modulation.
The data supply unit 56 supplies a data asset including a plurality of layers for hierarchical modulation.
The subtitle supply unit 58 supplies subtitle assets including a plurality of layers for hierarchical modulation.
The character super supply unit 60 supplies a character super asset including a plurality of layers for hierarchical modulation.

The multiplexing unit 62 generates a broadcast signal including at least a video asset, a data asset, and control information. The multiplexing unit 62 further generates a broadcast signal including an audio asset, a caption asset, and a text super asset. These assets are supplied by the video supply unit 52, the audio supply unit 54, the data supply unit 56, the caption supply unit 58, and the character super supply unit 60.
The transmission unit 64 transmits the broadcast signal generated by the multiplexing unit 62.

  The control information setting unit 66 sets control information for transmission. The control information setting unit 66 stores the location information (for example, base directory name) of the data file in association with each of the plurality of hierarchies in a predetermined table (for example, application information table) regarding the data asset. To do. The location for storing the location information (for example, base directory name) of each layer is, for example, in the MH-transmission protocol descriptor in the application information table. Further, in order to be able to distinguish layers in the MH-transmission protocol descriptor, for example, a value for each layer is defined in advance as a value of protocol identification (protocol_id). Similarly, for the subtitle asset and the character super asset, the control information setting unit 66 stores the location information (for example, base directory name) of each of the plurality of hierarchies stored in a predetermined table for each asset. You may make it store.

  As described above, the receiving apparatus according to the present embodiment determines which of the plurality of hierarchies is received when the broadcast unit receives a broadcast signal and when the broadcast signal is hierarchically modulated. A hierarchy determination unit that is determined based on the received broadcast signal, a separation unit that extracts at least a video asset and a data asset of the hierarchy determined by the hierarchy determination unit from the broadcast signal, and an extraction by the separation unit A video processing unit that outputs an image signal by decoding the video asset, a data processing unit that outputs an image signal by processing the data asset extracted by the separation unit, and at least the A video processing unit and a presentation unit that overlays and presents an image output from the data processing unit, and presents the separation. Is determined by the hierarchy determination unit among the location information (eg, base directory names) of each of the plurality of hierarchies stored in a predetermined table (eg, application information table) with respect to the data asset. A receiving apparatus that extracts a data file based on the location information of a hierarchy. The location for storing the location information (for example, base directory name) of each layer is, for example, in the MH-transmission protocol descriptor in the application information table. Further, in order to be able to distinguish layers in the MH-transmission protocol descriptor, for example, a value for each layer is defined as a value of protocol identification (protocol_id). In addition, for the subtitle asset and the character super asset, the separating unit of the receiving apparatus similarly stores the location information (for example, base directory name) of each of the plurality of hierarchies stored in a predetermined table for each asset. The data file may be extracted based on the location information of the hierarchy determined by the hierarchy determination unit.

  In addition, the transmission apparatus according to the present embodiment includes a video supply unit that supplies a video asset including a plurality of layers for hierarchical modulation, and a data supply unit that supplies a data asset including a plurality of layers for hierarchical modulation. A control information setting unit for setting control information for transmission, a multiplexing unit for generating a broadcast signal including at least the video asset, the data asset, and the control information, and the multiplexing unit. A transmission unit that transmits the broadcast signal, and the control information setting unit is associated with each of the plurality of hierarchies in a predetermined table (for example, an application information table) with respect to the data asset, A transmitting apparatus for storing location information (for example, base directory name) of a data file. The location for storing the location information (for example, base directory name) of each layer is, for example, in the MH-transmission protocol descriptor in the application information table. Further, in order to be able to distinguish layers in the MH-transmission protocol descriptor, for example, a value for each layer is defined as a value of protocol identification (protocol_id). Similarly, for subtitle assets and character super assets, location information (for example, base directory names) of the plurality of hierarchies stored in a predetermined table may be stored for each asset. .

In addition, you may make it implement | achieve at least one part of the function of the transmitter in each embodiment mentioned above in a computer. In that case, the program for realizing these functions may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible disk, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, a “computer-readable recording medium” dynamically holds a program for a short time, like a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line. In this case, a volatile memory inside a computer system serving as a server or a client in that case may be included, and a program that holds a program for a certain period of time.
The program may be a program for realizing a part of the above-described functions, or may be a program that can realize the above-described functions in combination with a program already recorded in a computer system.

Although a plurality of embodiments have been described above, the present invention can also be implemented in the following modifications.
For example, the number of layers in the hierarchical modulation is not limited to 2, and may be 3 or more. In the first embodiment and the second embodiment, when the number of hierarchical modulation layers is set to 2 (high hierarchy and low hierarchy), each method of the first embodiment and the second embodiment even when there are three or more hierarchies. Thus, a transmission device and a reception device can be configured.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  The present invention can be used for an apparatus for distributing content such as broadcasting. In addition, it can be used for a content distribution business using these devices.

1, 2 Broadcast system 3, 4 Transmitting device 5, 6 Broadcasting satellite 7, 8 Receiving device 21, 22 Receiving unit 23, 24 Hierarchy determining unit 25, 26 Separating unit 27, 28 Video processing unit 29, 30 Audio processing unit 31, 32 Data processing unit 33, 34 Subtitle processing unit 35, 36 Character super processing unit 37, 38 Presentation unit 51, 52 Video supply unit 53, 54 Audio supply unit 55, 56 Data supply unit 57, 58 Subtitle supply unit 59, 60 characters Super supply unit 61, 62 Multiplexing unit 63, 64 Transmitting unit 65, 66 Control information setting unit

Claims (2)

A receiver for receiving broadcast signals;
A hierarchy determination unit that determines which of a plurality of layers is received based on the received broadcast signal when the broadcast signal is hierarchically modulated;
A separation unit that extracts at least a video asset and a data asset of the hierarchy determined by the hierarchy determination unit from the broadcast signal;
A video processing unit that outputs an image signal by decoding the video asset extracted by the separation unit;
A data processing unit that outputs an image signal by processing the data asset extracted by the separation unit;
At least a presentation unit that overlays and displays an image output from the video processing unit and the data processing unit;
Comprising
The reception unit receives a broadcast signal including an entity of a single data file shared between the plurality of hierarchies with respect to the data asset,
The separation unit extracts the data file based on the location information common to the plurality of hierarchies with respect to the data asset,
In the case where the resolution of the image by the data asset is higher than the resolution of the image by the video asset, the presenting unit adjusts the resolution of the image by the data asset in accordance with the resolution of the image by the video asset. Process the image to lower the
A receiving apparatus. A computer having a receiver for receiving broadcast signals,
The program for functioning as a receiver of Claim 1.

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